Ceph-rust is a thin layer over the librados C interface. A little higher
abstraction layer will
be coming next that will encapsulate all of the "C" specific features so
that only pure Rust will be needed.

Ceph has a command system defined
in https://github.com/ceph/ceph/blob/master/src/mon/MonCommands.h
The cli commands mostly use this json based system. This allows you to
make the exact
same calls without having to shell out with std::process::Command.
Many of the commands defined in this file have a simulate parameter to
allow you to test without actually calling Ceph.